Posted on 08/30/2015 9:58:29 PM PDT by SunkenCiv
Explanation: Pluto is more colorful than we can see. Color data and images of our Solar System's most famous dwarf planet, taken by the robotic New Horizons spacecraft during its flyby in July, have been digitally combined to give an enhanced view of this ancient world sporting an unexpectedly young surface. The featured enhanced color image is not only esthetically pretty but scientifically useful, making surface regions of differing chemical composition visually distinct. For example, the light-colored heart-shaped Tombaugh Regio on the lower right is clearly shown here to be divisible into two regions that are geologically different, with the leftmost lobe Sputnik Planum also appearing unusually smooth. New Horizons now continues on beyond Pluto, will continue to beam back more images and data, and will soon be directed to change course so that it can fly past asteroid 2014 MU69 in 2019 January.
(Excerpt) Read more at 129.164.179.22 ...
[Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Inst.]
Well, you know, if that’s not a planet, I don’t know what is. Just sayin’
Hey! No fair!
*I* wanted to make the first whimsical nonsense post!
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"To Pluto And Far Beyond" By David H. Levy, Parade, January 15, 2006 -- We don't have a dictionary definition yet that includes all the contingencies. In the wake of the new discovery, however, the International Astronomical Union has set up a group to develop a workable definition of planet. For our part, in consultation with several experienced planetary astronomers, Parade offers this definition: A planet is a body large enough that, when it formed, it condensed under its own gravity to be shaped like a sphere. It orbits a star directly and is not a moon of another planet. |
Someone sure had to do it :-)
You know ... if you look at it a certain way...
The light colored part in the lower right could be a outline of Pluto’s head.
The piece on the far right is his muzzle, the body going underneath the planet and the semi-cratered area on the left is his ear flopping down.
See it?
(Anybody?)
I offer this, from memory: If you look up the JPL ephemerides of the planets, you will not find the earth! but rather, the obscure designation EMB, or Earth Moon Barycenter. So we may say that the earth and moon have been officialy recognized, ipso facto, as a double planet, as indeed they may be legitimately regarded. So I say, welcome Pluto and the Moon, to planethood!
The barycenter is below the surface of the earth.
Not a double planet.
Yup!
Clear as a bell ~
I think Bluto in Animal House is cuter.
I see that NASA has decided on the next target of New Horizons and will begin sending the rest of the photos of the Pluto flyby home soon.
I came across this some time ago when I saw a planetary ephemeris with EMB in place of the earth.
Consider this arbitrarily selected illustration:
I checked that the displacement of the barycenter from the center of the earth is accurate, even though the moon's distance is not to scale. The number is 4670/6390 = 0.73, which as illustrated, produces one heck of a wobble.
I don't see what significance there is in the relation to the earth's surface. It's not a case of "out of sight out of mind," is it? This criterion was obviously adopted just for the purpose of banishing the double planet bugbear ... BOO!
Finally. Clearly they have bandwidth issues, I blame Comcast. ;’)
Any two bodies where one orbits the other have a barycenter; this comes up once in a while, it reminds me of the “is a tomato a fruit or a vegetable” thing. The Earth:Moon mass ratio is something like 100:1. While the mass of Saturn’s moon Titan is something less than twice that of our Moon, Saturn’s mass is many times that of the Earth. The only planet:moon ratio in the Solar System that is known to be closer is that of Pluto and its moons.
Wikipedia’s partly nuts here:
> In cases where one of the two objects is considerably more massive than the other, the barycenter will typically be located within the more massive object. Rather than appearing to orbit a common center of mass with the smaller body, the larger will simply be seen to “wobble” slightly. This is the case for the Earth–Moon system, where the barycenter is located on average 4,671 km from Earth’s center, well within the planet’s radius of 6,378 km. When the two bodies are of similar masses, the barycenter will be located between them and both bodies will follow an orbit around it. This is the case for Pluto and Charon, Jupiter and the Sun, and many binary asteroids and binary stars.
Jupiter isn’t similar in mass to the Sun, as another page notes:
https://en.wikipedia.org/wiki/Planetary_mass#Planetary_mass_and_planet_formation
> The largest planet, Jupiter, is 0.09% the mass of the Sun, while the Earth is about three millionths (0.000003%) of the mass of the Sun.
Earth is about 1/318th the mass of Jupiter (the number is easy for me to remember, because 318 was the displacement of a very common V8 engine Chrysler used for decades), Jupiter (it sez there) is less than 1/10th of 1/100th, or 1/1000th the mass of the Sun.
This is clearly "pooh poohing" the case for E-M double planet status, which has a lot of support. A 73% displacement of the center of revolution from the earth's center is not a slight wobble!
There is also the question of lunar tides, which are very significant, not to mention the very large appearance of the moon in the sky.
And did you know that the Apollo flights never achieved escape velocity from the E-M system? A fairly close thing, I imagine ...
... Well, I just spent an undue amount of time studying the L1 point, which I determined to be 0.151 E-M distances from the moon, according to the quintic formula given in Wikipedia. It's a very steep ridge, as the numerics and the illustration show. Still couldn't say how deep the ridge is below "zero potential", but I think it's an interesting point.
Heh. Just now tuned in to the Science Channel, which happened to be showing THE SECRET HISTORY OF THE MOON. When I caught it, they were talking about the significance of a “supersized moon” for the history of life on earth. So, what do you want?
> the Apollo flights never achieved escape velocity from the E-M system...
Yes, that was the plan from the beginning — the craft arrived at the right spot at the right time for capture into lunar orbit. Buzz and others have said they could feel the Moon before they saw it, as it was moving in and the craft was heading into its sphere of influence, distance being more significant than mass.
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